화학공학소재연구정보센터
Journal of Vacuum Science & Technology B, Vol.21, No.6, 3032-3036, 2003
Fabrication of a continuous diamondlike carbon membrane mask for electron projection lithography
Fabrication of 8 in. high-performance continuous diamondlike carbon (DLC) membrane masks for electron projection lithography is described. The mask substrate materials and structures were optimized by evaluating the lithographic performance of the mask. The optimum mask consists of a sandwich structure, consisting of a thicker DLC scatter/a CrNx etching stopper/and a thin DLC support membrane on a bulk silicon wafer. The internal stress of each film component can be controlled by adjusting the film: deposition conditions. A DLC film can be easily etched by oxygen gas, and the CrNx etching stopper has a high etching durability. Highly accurate pattern properties can be obtained while also meeting performance requirements. The critical dimension accuracy of a DLC scatterer was less than +/-5% with a 280-nm-feature size in a 135 X 43 mm field. The electron aperture transmittance of a 44-nm-thick DLC membrane, measured by energy and angular distribution analysis for membrane, was 13 times as high as the 150-nm-thick SiNx membrane. (C) 2003 American Vacuum Society.